Dirty paper trellis codes have been introduced as an alternative to lattice codes to implement watermarking as communications with side information. Their key feature is robustness against value-metric scaling in comparison with lattice codes. Despite the strong academic recognition, parametrization issues remain unclear. For instance, the impact of the trellis configuration on performance is still not well understood. In this paper, experiments on synthetic signals are reported to investigate how the trellis configuration influences the bit error rate and the computational complexity